The output voltage of a rotary transformer varies with the rotor position. Therefore, the output voltage of the rotary transformer is generally used by a motor control system to acquire the rotor position.
The rotor position is generally acquired in two manners. In one manner, the rotor position is acquired by a rotary transformer decoder, and then a system microprocessor reads the rotor position via a serial or parallel communication link to the decoder device. In another manner, software decoding is applied, that is, the system microprocessor sends a sinusoidal excitation signal to the rotary transformer, receives a sinusoidal feedback signal and a cosine feedback signal from the rotary transformer via an analog sampling port of the system microprocessor, and performs calculation to acquire the rotor position by using a certain algorithm.
However, there is a risk of failure when the rotor position is acquired in the above two manners, and inaccurate detection results may lead to a critical system fault. Therefore, an issue to be solved by those skilled in the art is to provide a system for acquiring a rotor position of a rotary transformer, with which the reliability of the acquired rotor position can be improved.